Signaling system for railroads



March 3, 1931. H 1 E SIGNALING SYSTEM FOR RAILROADS Filed Aug. 16, 1929 QINV.

S2128 m2 28:9 me: 795:3 Lev 9.22 G.

ATTORNEY Patented Mar. 3, 1931 uurrsn res rareur 0mm osoan H. DICKE, or nocnns rnn, roan, assrenon TO GENERAL R ILW Y SIG-- nencomrsnr, or noorrns-rnn, NEW YORK SIGNALING ,SYSTEM RAILROADS Application filed August 16, 1929. Serial No. 388,381.

This invention relates to railroad signaling and interlocking systems and more particularly to means for safely indicating the position of a distant track switch and a switch machine controlling such track switch.

It is understood by those skilled in the art of railway signaling that it 1s very important a cuit the condition of a distant track switch by applying alternating current of a polarity corresponding to the posi ion of the track switch, and in including in said circuit a rec 25'; tilier. element which is poled in a direction to correspond to that of such track swltch.

In other words, the indicating means accord-- ing to the present invention resides in the 7 transmission of pulsating current of a par- Zi? ticular polarity and a particular phase relation. Another object of the present invention is to apply the polarity of the alternating current in accordance with one device,

Such for instance, a switch machine, and

$3 to insert a rectifier poled in accordance with some other device such as the switch points or by two different devices such as the switch points at opposite ends o'f a crossover, and a like.

Other objects, purposes and characteristic features of the invention will in part be obvious from the accompanying drawings and will in part be pointed out in the specification hereinafter.

In describing the invention in detail reference will be made to the accompanying drawings, in which the apparatus in the dotted rectangle represents the apparatus in an interlocking tower, and the remaining apparatus conventionally shown is that located at a distant way station. I

eeferring to the drawings the rails 1 of the main traclr of a railway system have been shown divided into track sections by insulating joints 2, and these rails 1 are at times connected to the sidingincluding rails 3,

through the medium of a track switch S, Associated with this track switch Sjis an east-bound main signal ME, an-east-bound dwarf signal DE, a West-bound main signal Mill and a take-siding signal Dl/V In the arrangement shown, the track switch S is, operated by a switch machine "Sill and Open ates the switch box contacts'5 and 6. i

This switch machine SM is controlled from the interlocking tower T through the medium of the lever. L and suitable control circuits conventionally indicated by the dotted line 7.

lnthe dispatchers oifice islo'cated suitable indicating means, which in the particular embodiment illustrated comprises polyphase alternating current three-position relay AC and three-position direct current polar r lay DC, connected in series. The relay DC is preferably shunted by a condenser 8 of --large' capacity, so that a large portion of the alternating current may pass through this condenser 8 rather than through the relay. DC. These indicating relays AG and'DC are at times supplied with energy from the distant way station through the medium of transformer 10 and the rectifier R, Although this rectifier B may be one of the electrolytic or thermionic type, it is preferably a rectifier of the copperoxide type, which latter type has a lower leakage resistance in the reverse direction therethrough; Having now described the elements f thesystelm it is believed expedient to consioerthe operation thereof, and the features ofsafet-y afforded thereby. I p

Operation-In the apparatus as illustrated in the drawings the track switch assumes the main track position, and with the switch machine indicating contacts 11 and 12 properly adjusted and with the throw rod and in.-

dicating rod properly intact, so that the switch box contacts 5 and 6 assume their proper position, renders the following indicating circuit complete :beginning atthe secondary winding of the transformer 10, wires 15 and 16, switcn machine contact 11, wires 1? and 18, switch box contact 5, rectifier R, switch box contact 6, indicating wire 20,

through relay DC insofar'as direct current loo ' return trickle-charge component is concerned and through the condenser 8 insofar as the alternating current component is concerned, wire 21, control winning of the relay AC, wire 22, common wire C, wire 23, switch machine contact 12, wire 2%, back to the secondary winding of transformer 10. The flow of pulsating current of a particular polarity, as de termined by the rectifier ll, d of a particular phase relation as deter .i or by the pole changing contacts l1 12, causes the DC relay to assume its righthand position by reason of the polarity of the direct cu nt com-- ponent and ca s s the AC to assume the 'ight-hand pos ion by reason of the phase relation of the alternating current component coasting with the fluxof the local winding this "ayAC.

It should be noted that the local winding; 25 of the relay AC is connected to the same trasmis on line .26 as is the transformer 10, l i" i the r ays 'AC and DC both energizedas ezrpl ed, the con tacts 27 and 28 of these rela s :11 and DC, respectively, assume their -it hand position and close a circui to levers for controlling non-conflicting si l such as the nals ME and MV], as indict. f, by the legend. In this connection it may be pointed out that these contacts 2? and 28 may also supply'enorgy to l vers controlling other the controlling devices which are non-conflicting and which are associated with the tracl plant.

' rectifier B would be shunted out and switch S, as would be the case in a large interloclu Attention invention. Obviously, a cross between the indicating line 20 and the common return wire C would not cause a false indication, be cause the relays AC and DC would, if anything, both be shunted and de-energized by such cross. Should a cross occur between. the

wires 17 and 23, this cross would also de energize the relays AC and DC. Should a cross occur between the wires 1? and 20,'this the relay DC wouldassume its de-energi ed position. This of course would cause the con-i tact 28 to assume its pendant position, there- 'by opening the circuit to the lever controlling signals ME and MVJ. Should direct cur be applied to the indicating wire 20 through some unauthorised path, it could produce no other effect than eifect de-energization or reverse energization of the relay DC, if this should hanp n no false indication could result, in that it requires both the relays AC and DC to assume corresponding positions in order to complete an indication circuit. Similarly, should alternating current of the same or some other frequency or the same or some other ph relation be applied to the is now directed to the feature of safety of the system embodying the present at the same time, and this is a very remote possibility, and in practice could be easily avoided by careful construction and insulation of the circuits and apparatus.

Let us now assume that the lever Leis operated to its reverse position and that this results in operation of the switch machine .to its reverse position BY Studying thecircuit heretofore traced, it becomes apparent that reversal of the switch machine SM reverses the instantaneous alternating current polarity, by reversing the connections of'the transformer 10 in the indication circuit, and

that movement of the switch pointsfto the v.

take-siding position reverses the pole changing switch box contacts 5 and 6, thereby reversing the polar arrangement of the rectifier R in said circuit. In other words, should the throw rod of the switch machine SM be broken, so that operation of the switch machine SM reverses the alternating current polarity but the rectifier R is not reversed in the circuit, only the alternating current relay AC would be moved to its left-hand positlon 1n whlch event neither of the circuits leading to the signal levers would be closed.

From this it seems that theswitchbox con-v, tacts 5 and 6 must be in a position corre relays AC and DC to corresponding positions. In the event, that thecontacts 11 and 12 are applied to one set of switch points of a cross over, and the contacts 5 and 6 are applied to the other switch points of the same cross over, it becomes apparent that the two switches of the cross over must be in cor responding positions in order to cause both of these relays AC and DC to assume corresponding positions'and render the indicatlon complete.

iii

' sponding to the position of switch machine contacts 11 and 12, in order to energlze the ick") lii to indicate the positions of two entirely different and separate instrumentalities, or the switch box contacts-56 may be connected to '10 "a cur. relay responsive distinctively to alcept as demanded by the scope of the following claims.

Vfhat I claim as new is 1. Indicating means for indicating with a high degree of assurance the position of a distant trafiic controlling device for railroads comprising, a polar relay responsive only to direct current, a three-position alternating current relay responsive distinctively to alternating current oi a particular polar'ty, a circuit including said polarrelay and said three'position relay, and means controlled by a distant traffic controlling device for causing the flow of alternating current having a particular phase relation and direct current of a particular polarity in said circuit at the same time. V

2. Indicating means for indicating with a high degree of assurance the position of distant traflic controlling device for railroads comprising, a polar relay responsive on to direct current, a three-position altern ternating current of a particular polarity, a circuit including said polar relay and said three-position relay, means'controll d by a distant traific controlling device for causing the flow of alternating current having a particular phase relation and direct current of a particular polarity in said circuit at the same time, and a control circuit controlled by said relays closed only when said relays assume corresponding positions.

3. Indicating means for indicating with a high degree of assurance the position of a distant trailic controlling device for railroads comprisin a polar relay responsive only to direct current, a three-position alternating current relay responsive distinctively to alternating current of a particular polarity, a circuitincluding said polar re and said three-position relay, means c olled'by a distant trafiic controllingidcvice i or causing the flow of alternating current having a particular phase relation and direct current of a particular polarity in said circuit at the same time, and a control circuit K controlled by said relays closed only when said polar relay and said three-position relay assume specific energized positions.

l. Indicating means for indicating with a highdegree of assurance the position of a 1 distant trafic controlling device for raillarity, a circuit including said polar relay,

and said three-position relay, two distant devices, means ior 'causingthe flow otalter nating current of a particular phase relati -n in said circuit when one of said two devices assumes a particular posi ion, and means for causing the flow of direct current or a P2111 ticular polarity in said circuit when the other of said devices assumes a p rticular position.

5. lndicatinn means for indicating with a high degree of assurance the position i distant traiiiccontrolling device for railroads comprising, a polar relay responsive only to direct current, a three-position alternating I current relay responsive distinctively to alternatlng current of a particular polar1ty,-a circuit including said polar relay, and said three-position relay, two "distant devices,

means tor causii the flow of alternating current of parti ular phase relation in said circuit when one of said two devices assumes a particular polarity in said circuit'when the other of said devices assumes a particular poing,'a threeposition polarized alterna curr .t relay,'athree-position polarduect current relay, a circuit including said three position relays, an alternating current source in said circuit, a re'ctiner in said circuit, means for reve alternating currei c in saidcircuit, means for reversing said rectifier in said enema; and means controlled in accordance with thc'positions or both. of said three-position relays. 7. Means for indicating whether two c.is-

tant tratiic controlling devices assume particular and corresponding positions comprising, a three-position polarized alternating rsing the connections of said current relay, a three-position polar direct current relay, a circuit including said threeposition relays, means atthe remote end or "said circuit for at times opening sai dlcircuit,

and means cont-rolled in accordance with the,

positions of both ofsaid threeosition relays.

8, Indicating means for in icatlng wlth a high degree of assurance the position of a d1stanttra1lic controlling devlce for rallroads comprising, an indicating clrcult, lndicating means in said circuit responsive only if two i distinct kinds of" current flow in said circuit, and means at a distant traffic controlling device for applying said two distinct kinds of current to said circuit when said traflic con-,

trolling device assumes a particular position.

9. Means for indicating whether two distant traffic controllin devices assume paricular and corresponding positions compris ing, a three-position polarized alternating,

current relay, a three-position polar direct current relay, a circuit including said threeposition relays, means at the remote end of said circuit for applying alternating current eta-polarity corresponding to the position assumed by one of said devices and for ap-' plying direct current of a polarity corresponding to the position assumed by the other of said devices to said circuit.

' 10. indicating means for indicating With a de ree of assurance the position of a disllic controlling device for railroads 1O coniprising a polar relay responsive only to direct current, an alternating current relay responsive distinctively to alternating cur rent of a particular polarity a circuit including said polar relay and said alternating our- 15 rent relay, and means controlled by said distant traliic controlling device for applying alternatingcurrent of a particular polarity to said circuit andinclnding. in seriesin said circuit a rectifier poled in aiparticular direc- 2Q tion When said traltic controlling device assuines a particular position. l ll. l s for indicating Whether tWo distant traffic controlling devices assume particular and corresponding positions comprising,

a polar alternating current relay at a local office a polar direct current relay at said local oiiice, a circuit leading from said oilice to said tWo distant traffic controlling devices including said relays, and means for applying alter- ,eo nating current of a particular polarity to said circuitwhen one of said traffic'controlling devices assumes a particular position and applying direct current of a particular polarity to said circuit when said other trallic controlling s5 device assumes a particular position.

12. Means Ifor indicating Whether tWo distant trailio controlling devices assume particular and corresponding positions comprising a polar alternating current relay at a local office,

40 apolar, direct current relay at said local office,

a circuit leading from said office to said tWo distant trafiic controlling devices including said relays, and means for applying current to said circuit of a polarity depending on the 45 position of one of said traffic controlling devices andinserting rectifier in said circuit poled in accordance with the position of said other trallic controllng device.

ln'testiinony whereof I affix my signature.

OSCAR H. DIOKE. 

